Convergence disorders and refractive amblyopia are among the most common and treatable vision problems seen in general optometric clinical practice. Oce- and home-based vision therapy (OBVT and HBVT, respectively) are standard treatments for such disorders. Recent advances in computerized video therapies that emulate vision therapy exercises performed in the optometrist's oce provide a lower-cost and more convenient alternative to OBVT. The downside of current commercial HBVT systems is that the recommended eye exercises are highly repetitive, monotonous, and uninteresting, which leads to high levels of patient noncompliance. This presents a problem since consistent performance and proper technique are key to achieving therapeutic benet. An alternative approach, which oers strong potential to increase the success of HBVT, is to incorporate vision therapy into fun and interactive computer games that patients will nd more engaging. To address this need, Barron Associates proposes to develop a novel computerized virtual reality HBVT system called iCare that will overcome the limitations of present systems by addressing three obstacles to successful home treatment: (1) patient compliance; (2) procedural accuracy; and (3) the ability of the optometrist to monitor training. The proposed approach takes advantage of advanced human-interface devices (HIDs) (e.g., Wii Remote Controllers) that have been developed for the video gaming market. Due to the popularity of video gaming, HID technology that would have been prohibitively expensive in the recent past is now widely available at low cost (e.g., < $40). These o-the-shelf HIDs permit the creation of virtual three-dimensional (3-D) environments on computer monitors (for \near-point vision therapy) or plasma displays (for \distance vision therapy). Traditional 3-D graphics technology based on \3-D glasses (i.e., red-blue anaglyphs) is static with respect to the frame of the viewing device; that is, the image is the same regardless of the viewer's position relative to the monitor. The proposed iCare technology exploits motion parallax via low-cost tracking of the patient's head position and orientation, creating a dynamic visual 3-D environment. Visually, the technology allows the viewer to perceive objects as if they are coming o of, or receding into, the screen. This enables the creation of virtual xation objects in a nearly innite 3-D space. Users can even see \behind and manipulate virtual objects. Under this SBIR Fast Track grant application, the proposing Team will develop and test prototype computer gaming environments for HBVT using the technology outlined above to improve treatment eectiveness. Phase I therapy will be aimed at treating refractive amblyopia in children 8-12 years of age; Phase II will focus on treating refractive amblyopia in teens and adults, as well as convergence insuciency in both populations. These disorders are clearly amenable to vision therapy and are common in clinical practice. For both vision problems, clinical studies of the comparative eectiveness of the most popular computerized HBVT programs vs. the iCare system's games will be conducted in children to assess the ecacy of the iCare system. PUBLIC HEALTH RELEVANCE: Convergence insuciency is one of the most common binocular vision disorders, and refractive amblyopia a vision disorder for which a very-high percentage of patients seek treatment; both disorders aect millions of U.S. children and adults. Such vision anomalies can cause a variety of chronic symptoms which, left untreated, often degrade academic and work performance; they may even result in learning disabilities in some cases. Computerized home-based vision therapy (HBVT) provides a relatively low-cost and convenient treatment option; however, the available commercial HBVT programs are highly repetitive and dull, leading to poor compliance. The goal of this research is to make HBVT a more eective alternative to oce-based vision therapy by incorporating the eye exercises into fun, interesting, and interactive computer video games that patients will nd more engaging, which should lead to better compliance and improved therapeutic outcomes.